Atom Spy Klaus Fuchs Jailed

The scientist was found guilty of betraying atomic secrets on March 1st, 1950.

Police photograph of Klaus Fuchs
Police photograph of Klaus Fuchs

The German-born, British atomic scientist Klaus Fuchs was 38 when, under the Official Secrets Act, he was found guilty of betraying atomic secrets to Soviet agents. The judicial process was rapid in dealing with him: Fuchs was arrested on February 2nd; committed for trial at Bow Street on February 10th; tried and sentenced at the Old Bailey on March 1st. As he had pleaded ‘guilty’ at the outset, the trial was equally swift, lasting less than two hours.

With the Cold War well under way, and in a climate of anti-Communism, little sympathy was afforded to a man guilty of supplying atomic secrets to the ‘enemy’. The maximum sentence ordained by Parliament was fourteen years, and that is what Fuchs received.

Born in Frankfurt on December 29th, 1911, Fuchs, like his Lutheran minister father, was to become deeply committed to socialist ideology, joining the German Communist Party in 1930. With the rise of Hitler, Fuchs’ political affiliation made him a ready target for the Nazis, resulting in him fleeing to Britain in 1934. Later he explained that it was actually the Communist Party that had sent him out of Germany ‘to finish studies’ that would enable him to contribute ‘in the building up of . . .[a] Communist Germany’. He finished his studies in Britain, obtaining doctorates in Philosophy and Physics, and won the Carnegie Research Fellowship in 1939.

A shy, reclusive man, the talents of this exceptional scientist were recognised by a professor at Birmingham University, who was then engaged on the ‘Tube Alloys’ programme – the cover name for the British atomic bomb research project. Accepting the call for assistance, Fuchs signed a security undertaking on June 18th, 1942. Within months he had become naturalised as a British subject, swearing the oath of allegiance to the King. In spite of his known political leanings he had been blithely admitted to Britain’s most secret nuclear work. His allegiance to Communism, however, took precedence over his newly-declared loyalty to the crown, and on learning of the significance of his work, Fuchs decided to make contact with Moscow via the Communist Party. Any doubts in his conscience were resolved through his Marxist philosophy, as his future confession revealed: ‘dialectical necessity of correct Party behaviour permitted espionage in the name of historical determinism’.

So important had his services become, that in December 1943, Fuchs was sent to the US as part of a research mission into atomic energy, assigned to the American atomic bomb programme – the Manhattan Project. After a stint at Colombia University, he was transferred to the weapons laboratory at Los Alamos, New Mexico. Throughout his 18-month stay, Fuchs continued to send the Soviets information of the utmost sensitivity (including details of the ‘Fat Man’ bomb dropped on Nagasaki) through a spy ring which included Harry Gold and Julius and Ethel Rosenberg. He probably knew as much then about the theory and design of the A-bomb as anyone in the world.

In 1946 he returned to Britain and became head of the theoretical physics division at the Harwell nuclear research station in Berkshire. He continued to pass secrets to the Russians, including the first design of the hydrogen bomb.

Suspicion of Fuchs’ spying finally came to light from US intelligence intercepts of Soviet signals traffic, known as Venona – in particular, a Soviet consulate message transmitted in 1944, but not deciphered until 1949. On January 27th, 1950, Fuchs confessed to MI5, apparently profoundly relieved at being discovered.

Fuchs’ espionage had a profound effect: the US hydrogen bomb effort was accelerated; and on March 8th, the Soviets announced that they, too, possessed the A-bomb. An American ban on the flow of atomic secrets to Britain was set for nine years. In 1959, after serving nine years in jail, Fuchs was released to Communist East Germany where he became deputy director of the DDR’s nuclear research institute. He died on January 28th, 1988.


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